Field of the Invention
The present invention relates to a push switch.
Description of the Related Art
There is known a push switch in which a movable board is moved in an operating direction of a knob by a push operation of the knob to cause a movable contact point provided on the movable board to slide on a fixed contact point (for example, Japanese Patent Laid-Open Publication No. 2001-243850).
FIG. 6A and FIG. 6B are diagrams for explaining the configuration of a push switch according to a conventional example represented by Japanese Patent Laid-Open Publication No. 2001-243850.
In a push switch 100 according to the conventional example, a movable board 104 having a movable contact point 104a is provided in a case 101 configured by assembling a cover 102 and a pole board 103 to be movable forward/backward in an operating direction of a knob 107 (upper-lower direction in FIGS. 6A and 6B).
The movable board 104 is positioned right under the knob 107 in the case 101, and an upper portion thereof is engaged to leg portions 108A and 108B extending downward from the knob 107 by an urging force acting on the movable board 104 from a spring Sp.
In the push switch 100, when the knob 107 moves downward in the side of the pole board 103 by the push operation of the knob 107, the movable board 104 is also pushed by the leg portions 108A and 108B of the knob 107 to move downward in the side of the pole board 103.
The movable contact point 104a is provided to project from a side face of the movable board 104, and makes push-contact with a fixed contact point 103a by an urging force of an unillustrated spring in a direction vertical to an operating direction of the knob 107, wherein the fixed contact point 103a is arranged to be lateral to the movable board 104.
The fixed contact point 103a is provided on a support wall 109 extending upward from the pole board 103, and is provided along a longitudinal direction (upper-lower direction in the figure) of the support wall 109 over a predetermined length.
Therefore, when the movable board 104 moves downward in the side of the pole board 103 by the push operation of the knob 107, the movable contact point 104a moves downward while sliding on a surface of the fixed contact point 103a. 
Here, the support wall 109 is provided with a step portion 109a projecting closer to the movable board 104 than the fixed contact point 103a at a lower portion of the pole board 103 in the side of a bottom wall portion 103c. Therefore, when the knob 107 is pushed down from a reference position showed in FIG. 6A to move to an operation position shown in FIG. 6B, the movable contact point 104a gets on the step portion 109a, so that a contact state of the movable contact point 104a with the fixed contact point 103a is eliminated.
In addition, in the push switch 100, the operation of the knob 107 is detected when the movable contact point 104a gets on the step portion 109a to bring in a non-contact state between the movable contact point 104a and the fixed contact point 103a. 
In the push switch 100 according to this conventional example, the movable board 104 (movable contact point 104a) positioned right under the knob 107 is moved forward/backward in the same direction as the operating direction of the knob 107 to connector disconnect the movable contact point 104a and the fixed contact point 103a. 
Therefore, since it is necessary to ensure a space for moving the knob 107 and the movable board 104 within the case 101, a thickness of the push switch 100 results in becoming increased in the operating direction of the knob 107.
Therefore, in the push switch in which the movable contact point making contact with the fixed contact point is caused to slide to connect or disconnect the movable contact point and the fixed contact point, it is required to thin the thickness of the push switch in the operating direction of the knob.